This invention relates to antennas, reflector antennas, and specifically to a multiband waveguide reflector antenna feed.
Contemporary military satellite communication (SATCOM) systems require cost-effective, light-weight, low-mass, multiband and polarization-agile antenna apertures. Specific SATCOM bands of current interest include C-band, X-band, Ku-band (10.7–12.7 GHz), K-band (20–22 and 29–31 GHz) and Q-band (43–45 GHz) for various military and commercial SATCOM systems. In addition, the ability to receive orthogonal polarized signals within the same band is a requirement for military SATCOM systems. An example of this is the requirement to simultaneously receive SCAMP MILSTAR (21-GHz right-hand circular polarization (RHCP)) and Global Broadcast System (GBS) video link (21-GHz left-hand circular polarization (LHCP)).
A traditional metallic waveguide feed 15 for a reflector antenna 10 is illustrated in FIG. 1 and represents the current art in reflector systems for portable communications. With the traditional waveguide feed 15 the realization of more than two bands is difficult. Multiband feeds can be mechanically large and therefore initiate excessive aperture blockage for many reflector applications. The feed assemblies are mechanically complex and difficult to manufacture, which adds to weight and cost. Such feeds are capable of circular polarization only and limited to two frequency bands.
Cluster feeds are commonly used on large satellite reflectors. They are mechanically complex and are not suitable for moderate and small-sized reflectors due to large aperture blockage.
A need exists for a low-cost, physically compact multiband reflector antenna feed for multiband polarization-agile communications-on-the-move and other microwave/millimeter wave multiband SATCOM systems.